Electbic-heateb-element retaining means



Jan. 1, 1929.

M. MURPHY ELECTRIC HEATER ELEMENT RETAINING MEANS Filed NOV. 11, 192'? Patented Jan. 1, 1929.

PATENT OFFICE.

MORTON MURPHY, F BUSHVILLE, INDIANA.

V ELECTRIC-HEATER-ELEMENT RETAINING MEANS.

Application filed November 11, 1927.

This invention relates in general to elec tric heaters of the type having a plate upon which food may be cooked or toasted, and in particular to means of assembling and retaining the heating element in association with the plate.

The principal objects of the invention are to provide a structure that permits the heating element to be held in close proximity to the plate; that may be assembled in multiples of individual units to obtain any desired plate area; that will permit quick heating of the plate with a minimum of current consumption; and that is X- tremely low in material and labor cost. Other objects will become apparent in the following description of one form off the invention. 7

Reference is made to the accompanying drawing, in which Fig. 1, is a fragmentary top plan view of a single toasting plate;

Fig. 2, a side elevation of the plate;

Fig. 3, a bottom plan view of the plate; and

Fig. 4, an end elevation of the plate with the component parts shown in disassembled relation.

Like characters of reference indicate like parts throughout the several views in the drawing.

I form a heating element by wrapping suitable resistance wire 6 about a rectangular sheet 7 of insulating material, preferably a thin sheet of mica. The sheet 7 is notched along the two opposite sides and the wire 6, preferably a flat, ribbon wire, is positioned in these notches. A thin sheet of mica 8 is laid on the top side of the sheet 7, and a similar piece 9 is laid against the back side of the sheet 7. I

'To heat the plate 10 as shown in Fig.1, three such heating elements as above described are employed to permit suitable interwiring to obtain low, medium and high heats. In this case a center element 11 is used that is slightly wider to have more resistance wire thereon than the elements 5 to either side. The element 11 is otherwise built up exactly as arethe'elements 5.

These three elements are placed edge to edge and fiat againstthe underside. of the Serial No. 232,632.

plate 10, a sheet of insulating material 12 is laid over the elements and completely covers the under face of the plate. Lugs 13 and 14 project downwardly from the under face of the plate 10, and a spider 15 is supported between the two lugs by means of the machine screws 16 passed through the lugs and lnto the upturned ends 17 and 18 of the longitudinal arm 19 of the spider.

Machine screws 20 are screw-threadedly passed through the arm 19 to press the plate 21 toward the plate 10, so as to compress and hold the sheet 12, and three elements 5, 11, and 5 therebetween.

The transverse arm 22 of the spider 15 carries the terminal blocks 23 and 24 at its respective ends directly above the above the edges of the pressure plate 21. These blocks carry the terminals 25 to which the wires from the elements are brought down through the slots 26 and 27 in the insulating sheet 12.

Toasters or stoves of various lengths are made up by placing a plurality of the unit plates 10 side by side on a suitable frame (not shown).

. I claim:

1. An electrical heating unit comprising a top plate having under side spaced-apart lugs, a flat heating element, an under plate having slots through which the lugs pass, a bar carried by the upper plate and extended under said under plate and having upturned ends which are bolted to the lugs, and means carried by the bartor pressing on said under plate to compressively retain said element against said upper plate.

2. An electrical heating unit comprising a top plate, a flat heating element, an under plate, a bar carried by the upper plate and extended under said under plate, and means carried by the bar for pressing on said under plate to compressively retain said element against said upper plate said bar being detachable from the plate and a terminal block carried on said bar.

3. An electrical heating unit comprising a top plate having under side spaced-apart lugs, an under plate, a fiat heating element between said plates, a compression member bolted to the lags of said upper plate and screw means passing through said member to press said under plate. 7 V

4. An electrical heating unit comprising a top plate, an under plate, a flat heating element between said plates, a compression member carried by said upper plate and screw means associated With said member plate toward said upper to press said under plate toward said upper plate, said compression member being eetaeliable and a terminal block carried by 10 the compression member In testimony whereof I affix my signature MORTON MURPHY. 

